We will continue our tissue culture infectivity studies with L-forms from the group A streptococci by employing the fluorescent antibody technique to determine the possibility of L-form fragments being carried along during tissue culture propagation. Also, three major enzymes involved in the synthesis of the rigid group A streptococcal cell wall will be investigated. They are (1) teichoic acid synthetase, (2) translocase and (3) peptidoglycan synthetase. Our aim in investigating these enzymes is to explain the inability of stabilized L-forms from this pathogenic group of bacteria to resynthesize a rigid cell wall.